The present invention relates to a light-sensitive sensor unit, in particular for automatic switching of lighting devices in vehicles.
Such a sensor unit is known from German Patent No. 195 23 262.3, which includes a global sensor and a directional sensor for detecting the lighting conditions outside the vehicle. The sensor unit is connected to the analyzer unit which determines from the signals of the sensor unit whether a change in the circuit state of the lighting device is necessary under the given lighting conditions prevailing in the surroundings of the vehicle. Although this known sensor unit permits automatic switching of the lighting device, it includes a relatively large number of parts due to the global sensors and the directional sensors, and this means a high cost and expensive adjustment.
The device according to the present invention has the advantage that a simple, compact, robust, easy-to-assemble and practically adjustment-free sensor unit is available due to the integration of the global and directional sensors. Furthermore, the device includes only a minimal number of components, which permits simple and inexpensive production with expanded functionality. The small dimensions which are possible due to the integration of the global and directional sensors have proven to be another major advantage, because the size of components on the windshields of motor vehicles which interfere with vision should be minimized.
Due to the fact that at least three sensors detect light from predetermined directions, a wider range in front of the vehicle is detected. If at least one sensor is arranged in the direction of travel and the two other sensors are arranged, pivoted out of the direction of travel by an angle a on both sides, this yields a wide cone of detection in front of the vehicle, so that even the entrance of a tunnel which is not yet in the direction of travel can be detected and the lighting devices controlled accordingly.
If the directional sensors have lens-like elements, which may also have a smooth transition between them, the detection cone may be adjusted individually to the wishes of the automobile manufacturer.
Integration of the light guide body of the sensor unit into a light guide body of a rain sensor device makes it possible to eliminate additional components and to further w reduce the number of components on the windshield which interfere with vision, in particular when the light guide body is manufactured in a multicomponent injection molding process together with the light guide body of the rain sensor and the coupling medium.